Fan



Feb. 1, 1938. L. ZAIGER 2,107,136

FAN

Filed Sept. 25, 1937 2 SheebS-She-et 1 5 1232s 1o 12 H7 f f, lnvenToT, 6.81221 1926 l539 15 12 Louls Zanger J WMMQW l:lili

Patented Feb. '1. 1938 nutren) srnrns .PATENT cri-ice e claims.

closing the blades of a fan in a guard member to prevent a person from becoming injured by contact with the rotating blades,

In my improved fan the blades are of suiiicient 10 rigidity to hold their shape and pitch while in operation, but the peripheral portion of the blades is sumcientlyv soft so that a person will not be injured if he accidentally contacts the rapidly rotating blades.

w A further object of the invention is to provide.

.a novel way of making a fan having this construction.

In' the drawings wherein I have shown a se-- lected embodiment of my invention: 20 Fig. l is a face view of the fan element with a portion broken out; Fig. 2 is an edge view thereof;

Fig. 3 is a view of the core member; Figs.' 4 and 5 are sectional views oi the mold 25 which is used in molding the rubber covering to the core member, Fig. 4 showing the mold opened with the rubber sheets and core member' in place and Fig. 5 showing the mold closed and the f an member molded into shape;

Fig. 6 is a view on a small scale on one mo the rubber sheets used in forming the rubber covering for the fan; y Fig. 7 is an enlarged section on the line 'l-l, Fig. l;

bers used for deforming the fan blades to give them the required pitch;

Fig. 9 is a side view of the die in partly open 40 position and with the fan element in position to be acted on by the die;

Fig. 10 shows the die closed. My improved fan element is formed with a. plurality of blades, each of which has a metal core 4 which is covered. with rubber, therubber extending beyond the peripheral edge of the core for Fig. 8 is a plan view of one ot the di mem.

(El. 230-26l) pitch. This may be done conveniently by means oi a suitable die.

In the drawings, I indicates a fan element embodying my invention. The fany element shown is vformed with four fan blades 2. Each fan 5 blade presents a core portion 3 of sheet metal which is provided with a rubber covering on both sides as indicated at Il. This rubber covering not only completely covers the core but extends for a considerable distance beyond the peripheral edge 10 5 of the core as shown at 6 so that the peripheral marginal portion of the `fan element is formed of non-reinforced rubber and is relatively soft and exible.

One way of making my improved fan is to first l5 provide a core element 'I which is shown in the form of a disk of considerably smaller diameterv than the diameter of the fan element and which is also formed with radial slots 8 extending from its periphery well toward its central portion. The 20 core element is thus petaliform in shape and has a petaled formation, it presenting a central portion 9 from which radiate thepetal sections or sectors 3, one for each of the fan blades, each petal section 3 forming the core of its' blade 2. The central portion 9 of the core is shown as provided with an opening I0 and also with a plurality of apertures il, the purpose of which are to assist in correctly positioning the core element both in the mold by which the rubber covering 4 is molded to the core and in the die by which the blades are given the required pitch angle. If desired also, I may make each of the sectors il' oi the core element with additional apertures I2. This core element 'I maybe readily stamped from sheet metal and when it is first made it is iiat with the sectors all occupying the same plane.

After the core element has been made then the rubber covering 4 lis applied thereto in such a. way as to form not only a rubber covering for 40 the sides of the sectors t but also so as to form the extendedperipheral portion 6 of rubber which projectsy beyond the periphery of the core.

While this may be done in various ways I nd itis convenient to accomplish it by placing the 45 fiat core between two sheets of rubber which are larger than the core, and then subjecting the superposed rubber sheets and core to a molding operation to mold the rubber to the core and to cause the portions of the sheets beyond the pe 50 riphery of the core to be Welded together. thereby to form the rubber portion 6 ofthe blade.

This operation is illustrated in Figs. 4 and 5 which show a mold comprising two mold members I3 and Il. The mold member I3 is formed 55 with mold cavities I5, one for each blade of the fan, and with the central hub-forming cavity I8. The other mold I4- is shown as having flat moldingface I1 and a central hub-forming cavity I9. The mold I5 is shown as having positioning pins I9 properly positioned to be received in the positioning apertures II of the core member 1, and it is also shown as provided with a center pin 20 which is somewhat smaller than the central opening I 9 of the core member.

In forming the fan I propose first to place a small piece of sheet rubber 2I in the mold member I2 at the central portion thereof and then to superpose on this a larger sheet 22 of sheet rubber. .Both the sheet 2I,`if it is used, and the larger sheet 22 may be provided with a central aperture 22 to receive the pin 20 and with other apertures 24 to receive the positioning pins I9.

It desired, however, the apertures 22. 24 in the interposed between the rubber sheet 25 and the.` core member or placed on top of the sheet 25.

After these rubber sheets and core member have been properly assembled as shown in Fig. fi, then the mold is closed as illustrated in Fig. 5. 'Ihis will mold the rubber sheets to the sectors 2 of the core element 1 and will cause the rubber t6 ilow into the hub-forming cavities I5 and I3 of the mold members, thereby to form the hub portion I9 of the fan element. The rubber is also forced through the apertures I2 of the sectors 2 and through the central aperture I9 of the core member and around the positioning pins I9 and the center pin 29. The pressure to which the rubber is subjected when the molds are closed not only forces the vsurplus rubber into the hubforming cavities I9 and I4 to form the hub 49. but results in welding together the rubber sheets 22, 25 where they meet beyond the periphery of each core sector 2, thereby forming the portions 9 of the blades,

This molding operation is performed while ithe core member kin a nat condition and it results in producing a fan element in which the blades 2 all occupy the same plane.

When the fan element is removed from the mold any surplus rubber which may have been squeezed out through the joint between the mold members is trimmed oi! thereby leaving the fanv element in the condition shown in Fig. 1. In this condition the hub portion 49 thereof will be provided with a central opening 21 which is formed -by the central. pin 29 and with other smaller l openings 29 which are formed by the positioning 65 give each blade the required pitch. A die suitable for this purpose is illustrated in Figs. 8 to 10, and it consists of two die members 2I, 32. Each die member is formed with a plurality of deforming sectors, one for each blade of the fan, the sectors of each die member being opposite to the sectors of the other die member and the faces of opposing sectors having the proper shape to deform or twist the fan blades in order to give them the required pitch. The deforming sectors of the die member 22 are indicated at 22 and each deforming sector 22 is provided with the operative inclined face 24.. 'I'he deforming sectors of the die member 3| are indicated at 35 and each of these is provided with the operative inclined face 25.

'Ihe die member 22 is provided with a central spring-pressed plunger 21 which terminates at its upper end in a cup-shaped head 38 having an interior shape to ilt the portion 29 of the hub 49, said head 22 having positioning pins 40 rising therefrom adapted to enter the apertures 28 in the hub of the fan element and a center pin 4I of a size to fit the center aperture 21 of the fan element. The plunger 21 is shown as acted on by a spring 42 which tends to hold it in its projected position and it is adapted to be forced downwardly into the die member 22 against the action of the spring 42 when the two members are closed together, as shown in Fig. 10. A screw or pin 42 carried by the die member 22 and having one end operating in a groove 44 in the plunger serves to limit the movement of the plunger relative to the die. 'I'he die member 2I is also provided with` a spring-pressed plunger 45 which terminates at its outer end in a cupshaped head 45 that is of a size to fit the portion 41 of the hub 49. This plunger is acted on by abspring which normally holds it in-the projected position shown in Fig. 9. f

In deforming the blades of the fan to give them the required pitch the fan element in its flat shape shown in Fig. 1 is placed in position between ythe dies with the positioning pins 40 and 4I occupying the apertures 29 and 21 in the hub portion of the fan as seen in Fig. 9. .The two die members are then closed together and during the initial closing movement the cup-shaped head 46 of the plunger 45 is brought against the portion 41 of the hub of the fan element so that the hub portion will beclamped between the cupshaped heads 45 and 29. As the dies continue to move together one sidey edge of each blade 3 engages the high portion of the corresponding die sector 23 and the opposite side edge of the blade is engaged by the high edge of the opposing die sector 25, and as the die members are closed together the blades of the fan are twisted or deformed as illustrated in Fig. to give each blade the required pitch. During this operation the sectors 3 of the core elements are twisted into the inclined positions determined by the-faces 34 and 35 of the opposing die sectors, and the rubber portion of the fan is distorted from its original fiat shape. The deformed petal sections 2 of the core serve to preserve the pitch angle which is thus given tothe blades by the die members, notwithstanding the tendency of the distorted rubber portion of the fan to resume its initial shape. While the shape of the blades 2 may vary somewhat without departing from the invention, yet the shape of the blade whichI prefer is substantially like that herein illustrated in which the dimension from the leading' edge to the trailing edge is at least as great as the dimension in a radial direction. This results in a fan element which, when taken from the mold, has a petalated formation. Furthermore, in the preferred embodiment of the invention the width dimension of each petal section 3 of the core is such that said petal section extends throughout the major portion of the blade in the direction of the width of the blade. 'I'he radial dimension of each petal section 3 of the core, however, has such relation to the radial dimension of the corresponding blade 2 that a considerable portion of each blade is located beyond the peripheral edge 5 of said petal section as shown at t. As stated above, this unreenforced portion t of each blade will yield or give when it strikes an object but it has the capacity to resume its normal shape and radial position as soon as it is .free from 'said object.

The blades, therefore, might be described as selfsustaining blades which are sumciently flexible to yield when engaged by an object but which have the capacity to resume their normal shape when `free from said object.

A fan element is thus produced which has rubberv blades that are sulciently reinforced interiorly at their inner ends where they join the hub portion of the fan to preserve the pitch which has been given to the blades by the die members, but the outer marginal portions of which are formed of non-reinforced rubber and are, therefore, soft and flexible. The reinforced portion of each blade preserves the pitch of the blade throughout its extent but the outer peripheral half of the blade is formed from non-reinforced rubber. A fan element having this construction presents blades which aresufficiently rigid tov have excellent air-movingA qualities but at the same time the outer peripheral portion of the fan is of soft flexible material which will not cause injury to a person if he contacts with the fan when it is rapidly rotating.

Afan having my improved fan element can, therefore, be safely used in any location Without enclosing the rotating fan element in a guard as is usually done in the case of a fan having metal blades. 'I'he central opening 27 in the hub of the fan provides a suitable opening to receive the end. of the fan shaft to which the fan element may be applied, and in the case of a small fan such as is used in automobiles for circulating air against the windshield a sufficient driving connection between the fan element and the fan shaft can be provided by simply forcing the rubber hub oi' the fan element onto the end of the shaft especially if the shaft has a diameter slightly larger than thatof the aperture 2li. Since the fan ele-y `merit is initially made with a flat shape shown in Fig. l and without any `pitch angle to the blades, the deforrning of' the blades to give them the required pitch angle distorts the rubber portion of each blade and, therefore, in the completed fan the rubber portions of the blades are maintained in their distorted condition by the petal sections of the core member.

This application is a continuation in part of my co-pending application, Serial No. 137,502, filed April 1'?, 1937.

.I claim:

1. A f an element having a hub portion and a plurality of blades molded to shape from rubber,

lthe dimension of each blade from the 'leading to the trailing edge being at least as great 'as the radial dimension thereof, and the hub portion and the inner radial end only of each blade being intefan in which each blade is interiorly reinforcedV at its inner radial Aend and the outer radial portion of which is soft and iexible;

3. A fan 'element having a petaliform core portion of sheet material and rubber enclosing each petal section of the core portion toform the blades of the fan and also enclosing the central part of the core portion, said rubber having con- A,

siderable thickness at said central part of the core thereby to form a rubber hub ,for the fan, the rubber portion of each blade extending `radially `considerably bey'ond the periphery of its petal section of the core to provide an outer radial portion for y,the blade which is suiiiciently fiexible to yield when it engages an object but which is capable of resuming its normal shape when free from. said object.

4. A fan element having a petaliform core portion and rubber enclosing each petal section of the core portion to form the` blades of the fan and also enclosing the center of the core portion and forming a rubber hub for `the fan, the rubber portion of each blade extending-radially considerably beyond the periphery of its petal section of the core to provide an outer radial portion for the blade which is suiiiciently flexible to yield when it engages an object but which is capable of' resuming its normal shape when free from said object, said rubber hub portion of the fan element having an axial shaft-receiving opening. i

-5. A fan element comprising a hub and' blades formed of rubber, the dimension of each blade from the leading to the trailing edge being at least as great as the radial dimension thereof.

and a petaliform core member of sheet material embedded in and entirely enclosed by the-rubber with a petal section of said core located at and reenforcing the inner radial end only of each blade, the outer radial portion of each blade being free from reenforcement and being self-sustaining but suiciently flexible to yield when engaged by an object and capable of resuming its normal shape when free from said object.

6. A. fan element presenting a petaliform core portion of sheet metal, the petal sections of which have a pitch angle corresponding to the pitch angle required in each blade of the fan and an integral rubber portion which covers the core portion andrforms both a rubber hub for the fan and the blades thereof, the rubber part of each blade extending radially considerably beyond the periphery of the petal section thereof and normally having a 'less pitch angle than that of the corresponding petal section, the rubber portion of each blade being held in distorted condition at said required pitch angle of the blade by the corresponding petal section of the core, the outer radial portion of each blade being sufficiently flexible to yield when it engages an object but DISCL Disclaimer led June 15, 1940, b

AIMER FAN. Patet dated February 1, 1938., y the inventor.

Herb enters this disclaimer to claimsv 2, 3, 4, and 6 in said speccation.

Gazette July 9,1940] 

